Some driver objects (e.g, Sessions, Transactions, Result streams) are not safe for concurrent use. By default, it will cause hard to interpret errors or, in the worst case, wrong behavior.
To aid finding such bugs, the driver now detects if the Python interpreter is running development mode and enables extra locking around those objects. If they are used concurrently, an error will be raised. The way this is implemented, it will only cause a one-time overhead when loading the driver's modules if the checks are disabled.
Obviously, those checks are somewhat expensive as they entail locks (less so in the async driver). Therefore, the checks are only happening if either
Python is started in development mode (python -X dev ...) or
The environment variable PYTHONNEO4JDEBUG is set (to anything non-empty) at the time the driver's modules is loaded.
Some driver objects (e.g, Sessions, Transactions, Result streams) are not safe for concurrent use. By default, it will cause hard to interpret errors or, in the worst case, wrong behavior.
To aid finding such bugs, the driver now detects if the Python interpreter is running development mode and enables extra locking around those objects. If they are used concurrently, an error will be raised. The way this is implemented, it will only cause a one-time overhead when loading the driver's modules if the checks are disabled.
Obviously, those checks are somewhat expensive as they entail locks (less so in the async driver). Therefore, the checks are only happening if either
python -X dev ...) orPYTHONNEO4JDEBUGis set (to anything non-empty) at the time the driver's modules is loaded.